On the relations between the Zagreb indices, clique numbers and walks in graphs. (English) Zbl 1462.05079
Summary: H. Abdo et al. [MATCH Commun. Math. Comput. Chem. 72, No. 3, 741–751 (2014; Zbl 1464.05049)] demonstrated that there exist connected graphs for which \(\mu^2(G)\approx M_2(G)\) where \(\mu(G)\) is the spectral radius of a graph \(G\), \(M_2(G)\) is the second Zagreb index and \(m\) the number of edges. We use and extend this approximation to investigate opportunities to convert results from spectral graph theory into results involving the first and the second Zagreb indices \(M_1(G)\) and \(M_2(G)\). We do this principally by noting that \(M_1(G)=w_3\) and \(2M_2(G)=w_4\), where \(w_3\) and \(w_4\) are the numbers of 3- and 4-walks in a graph, respectively.
MSC:
05C09 | Graphical indices (Wiener index, Zagreb index, Randić index, etc.) |
05C07 | Vertex degrees |
05C92 | Chemical graph theory |
92E10 | Molecular structure (graph-theoretic methods, methods of differential topology, etc.) |
05C12 | Distance in graphs |